DEVICE FOR COUPLING TWO BOATS

Abstract

A device for rapidly remotely coupling together two vessels, in particular a first ship or floating support and a second ship, comprises: at least one floating and docking structure fastened to or suitable for being releasably fastened to the side and/or the keel of the hull of a second vessel; and at least two actuators spaced in succession from one another in the longitudinal direction of the first vessel. The actuator cylinder of each the actuator is arranged to be fastened to the side of the hull of the first vessel, using a first fastener and pivot hinge device. The end of the rod of each actuator is arranged to be fastened to or suitable for being fastened to the floating and docking structure via a second fastener and pivot hinge device.

Claims

1.-15. (canceled)

16. A device for remotely coupling together two vessels, in particular a first vessel in a first ship or floating support and a second vessel in a second ship, the device comprising: at least one floating and docking structure comprising at least one docking float suitable for being ballasted and de-ballasted in order to enable said floating and docking structure to be immersed in controlled manner, and at least one docking element fastened to or suitable for being releasably fastened to the hull of a second vessel; and at least two actuators spaced in succession from one another in the longitudinal direction of the first vessel, one end of the actuator cylinder of each said actuator being fastened to said first vessel using a first fastener and pivot hinge device, and the end of the rod of each actuator being fastened to or being suitable for being fastened to a said floating and docking structure via a second fastener and pivot hinge device.

17. The device according to claim 16, wherein said actuators in the retracted position and fastened to said floating and docking structure via said second fastener and hinge devices are suitable for being positioned together, vertically or in a position close to the vertical, against the hull of the first vessel, and out of the water when said floating and docking structure is not fastened to a said second vessel and said docking float is de-ballasted.

18. The device according to claim 16, wherein said first and second fastener and pivot hinge devices at the end of each actuator each make possible at least a first pivoting movement of said actuator about a horizontal first axis perpendicular to the longitudinal axis of said actuator, and a second pivoting movement of said actuator about a second axis perpendicular to the longitudinal axis of said actuator and situated in a vertical plane containing the longitudinal axis of said actuator, and said first and second fastener and pivot hinge devices at the ends of each actuator also made possible a third pivoting movement about the longitudinal direction of the actuator.

19. The coupling device according to claim 16, wherein when the rod of each said actuator is fastened to a said floating and docking structure, said actuator is arranged above the surface of the sea horizontally or with the actuator rod sloping relative to a horizontal plane at an angle of less than 15 degrees while remaining out of the water, the cylinders of said actuators being fastened to the side of the hull of said first vessel at the same height.

20. The coupling device according to claim 16, wherein when said actuators are fastened to said floating and docking structure, they are arranged parallel to one another and/or sloping at an angle of less than 30 degrees relative to a vertical plane perpendicular to the vertical plane that is tangential to the side of the first vessel.

21. The coupling device according to claim 16, wherein said actuators are double-acting hydraulic actuators having rods that are set to an initial coupling extension position and having a hydraulic circuit that is adjusted and/or automatically controlled in such a manner that any departure from said initial coupling extension position is corrected in order to reestablish the desired spacing between the two vessels, and to reestablish the initial extension of the actuator rods.

22. The coupling device according to claim 16, wherein said floating and docking structure comprises at least one attachment element suitable for attaching to the second vessel while said float is ballasted at least in part and said attachment element is underwater, said attachment element presenting an arrangement and/or shape making it suitable for being positioned under the bottom of the second vessel by ballasting said docking float and then for pressing against and/or facing the bottom of the second vessel by partially de-ballasting said docking float.

23. The coupling device according to claim 22, wherein said attachment element suitable for being underwater is situated on said floating and docking structure at a height such that when the float is de-ballasted and said actuators are safely positioned against the first vessel, said attachment element is out of the water.

24. The coupling device according to claim 16, wherein said attachment element of the floating and docking structure for attaching to said second vessel includes magnetic or pneumatic suction cups suitable for pressing against the side and/or the bottom of the second vessel.

25. The coupling device according to claim 16, wherein said attachment element is constituted or supported by a portion of the floating and docking structure that forms a fork suitable for extending under the bottom of the hull of the second vessel from side to side and supporting magnetic or pneumatic suction cups suitable for bearing against the bilges of the hull of the second vessel.

26. The coupling device according to claim 16, wherein it has a single said floating and docking structure constituted by beams and/or tubes assembled together in a truss assembly forming a tower having at least one said float underwater suitable for being ballasted.

27. The coupling device according to claim 26, wherein the tower has a tubular structure of rectangular parallelepiped shape.

28. The coupling device according to claim 26, wherein the at least one float underwater suitable for being ballasted is in the form of a cylinder and/or a rectangular caisson that is integrated in or supported by said floating and docking structure.

29. The coupling device according to claim 16, wherein said floating and docking structure extends: a) heightwise from under the hull of said second vessel to at least above the deck of said second vessel, preferably over a height lying in the range 60 m to 100 m; and b) in the longitudinal direction of the second vessel over a length that is at least one-fourth of the length of said second vessel.

30. An assembly of two vessels remotely coupled together using a coupling device according to claim 16.

31. The assembly of two vessels according to claim 30, wherein said coupling device provides coupling between a first vessel which is a floating support of the type including an installation for liquefying or regassifying gas, and a second vessel of the methane tanker type.

32. A method of implementing a coupling device according to claim 16, wherein the following steps are performed: a) with said actuators being in a retracted position and said floating and docking structure with at least one said de-ballasted float being fastened to said actuators via said second fastener and hinge devices, and said actuators being pressed at least in part out of the water against and/or above the hull of the first vessel, said float(s) is/are ballasted in order to immerse said floating and docking structure to the appropriate depth for fastening it to the second vessel, and said actuators are pivoted and deployed together in order to fasten said floating and docking structure against the second vessel; b) with said actuators deployed in an initial coupling position of medium extension and with said floating and docking structure fastened to said actuators via said second fastener and hinge devices and being fastened to said second vessel via said attachment element(s), with a said float being ballasted, said actuators are actuated in extension and/or said actuators are controlled automatically so that said actuators and the two vessels remain in their initial position or return towards the initial position with a distance between the two vessels being controlled in the event that they depart therefrom; and c) with said actuators being deployed in an initial coupling position of medium extension and said floating and docking structure being fastened to said actuators and to said second vessel, and with said float ballasted, said floating and docking structure is separated from said second vessel, and then said actuators are retracted and said float is de-ballasted in order to cause the actuators to pivot and be pressed at least in part out of the water against and/or above the hull of the first vessel.

Description

[0057] Other characteristics and advantages of the present invention appear better on reading the following description made in illustrative and non-limiting manner, with reference to the accompanying drawings, in which:

[0058] FIGS. 1A and 1B are views of a first preferred embodiment of the device 1 of the invention in the coupling position, fixed to and between the first vessel of the FLNG type and the second vessel of the LNGC type (FIG. 1A), and also in the absence of the second vessel (FIG. 1B);

[0059] FIGS. 2A and 2B are views of a second embodiment of the device 1 of the invention in a stowed position fixed against the hull of a first vessel of the FLNG type (FIG. 2A), and in the coupling position between two vessels (FIG. 2B);

[0060] FIGS. 3A to 3C show the floating and docking structures 3 in the first, second, and third embodiments (FIGS. 3A, 3B, and 3C) of the coupling device of the invention; and

[0061] FIG. 4 is a detail view of an actuator 2, 21-24 with its two fastener and pivot hinge devices, 2c1 for connection to the first vessel 10 of the FLNG type, and 2c2 for connection to a tubular element 31 of the tower of the floating and docking structure 3.

[0062] In FIGS. 1A-1B, 2A-2B, and 3A-3C, the floating and docking structure 3 comprises an open structure forming a tower made by assembling together a plurality of vertical tubes 31 arranged so as to form at least the four edges of said tower and so as to support a top platform 3c. The tower is connected to the first vessel 10 by actuators 21-24 as described below. Each vertical tube 31 is assembled to each of the other two adjacent tubes 31 that are the closest, a) by first horizontal junction beams or tubes 32a perpendicular to the axis of the tower, and b) by second junction beams or tubes 32b arranged to slope in chevrons or on diagonals, possibly crossing one another between two of said vertical tubes 31. On its top face, the tower supports a platform 3c suitable for receiving a technical intervention crew that may access it, by way of example, from the first vessel 10 via gangways 40 as shown in FIG. 3C.

[0063] The tower is fitted with the mooring system 3b, 3b1-3b2 forming a said attachment element for attaching said floating and docking structure to the hull of the second vessel 11. Said attachment element or mooring system may comprise a system of plates having suction cups or magnetic fasteners 3b.

[0064] In the first preferred embodiment of FIG. 3A, the attachment element comprises four of said plates 3b fitted with suction cups or magnetic fasteners arranged on the top faces of two pairs of cantilevered-out horizontal tubular elements 33b constituting a fork 33 that extends horizontally forward outside the tower towards the second vessel from the face of the tower facing the vessel. These horizontal tubular elements 33b are supported by sloping lower tubular elements 33a forming a fork 33 extending in the horizontal direction over a length L3 covering the width of the hull 11b of the second vessel and supporting four plates which may merely be supports and/or which may be magnetic fasteners, such as magnetic suction cups 3b. In FIG. 3A, these plates 3b slope so as to bear against the bilges 11c on either side of the hull (junction zone between the side 11a and the keel 11b), or two pairs of plates 3b sloping systematically in opposite directions on either side. In this example, the width L3 is about 50 m, which is representative of the largest methane tankers and makes it possible to receive 30 m wide methane tankers. The offset longitudinal end of said fork is supported by floats 3a in the form of vertical cylinders 3a1 suitable for being ballasted and/or de-ballasted. Other lower tubular portions 3a2 of the tower constitute floats in the form of cylinders suitable for being ballasted and/or de-ballasted.

[0065] The floating and docking structure 3 shown in FIG. 3A is an open structure constituted by tubular elements that are assembled together in a truss assembly forming a tower of rectangular parallelepiped shape having a height H1=89.5 m, a length L1=60 m in the longitudinal direction of the two vessels, and a width L2=20 m in the direction perpendicular to said longitudinal direction for mooring together two vessels that are 150 m to 300 m long.

[0066] In the second preferred embodiment of FIG. 3B, said docking element comprises a pair of cantilevered-out horizontal tubular elements 33b forming a fork 33 extending horizontally forwards over a shorter length L3=15 m. In the bottom portion of the tower of FIG. 3B, at about H2=20 m from its bottom end, the tower supports or incorporates floats 3a in the form of cylinders 3a3 and 3a4 having a diameter in the range 2 m to 3 m and respectively of length L2=20 m for 3a4 and L1=60 m for 3a3, which cylinders are arranged horizontal forming a rectangular belt connecting together the vertical tubes 31 at the edges of the rectangular parallelepiped having the same height H1 of 89.5 m.

[0067] In FIG. 3C, in a third embodiment, the floating structure 3 comprises a tower supporting floats 3a comprising four buoyancy caissons 3a1-3a4 of rectangular parallelepiped shape, of which two 3a3 and 3a4 are in the bottom portion of the tower, and two 3a1 and 3a2 are under the forward end of the fork 33. The fork 33 supports three plates 3b arranged in a triangle, with one plate being beside the tower and two plates sloping in the opposite direction being beside the ends of the two branches of the fork. The distribution of thrust between the cylindrical members 31, 32a-32b, 33a-33b of the tower and these four caissons 3a1-3a4 is 2600 metric tonnes force for the cylindrical members compared with 1700 metric tonnes force for the four caissons 3a1-3a4. In FIG. 3C, the dimensions of the floating structure 3 and of the fork 33 are L1=40 m, L2=20 m, and L3=55 m.

[0068] In FIGS. 2A-2B and 3B, the support plates or magnetic suction cups 3b comprise three vertical plates 3b2 on the outside face of the tower and two horizontal plates 3b1 on the top face at the end of the fork 33 that become pressed against the side 11a and the bottom 11b respectively of the second vessel 11. More precisely, in this embodiment, on a face that faces the second vessel, the tower supports: [0069] three magnetic or pneumatic suction cups or plates in the top portion of the tower, arranged in a triangle forming vertical top plates 3b2 suitable for pressing against and fastening to the flank of the second vessel at the top portion of the tower; and [0070] two magnetic or pneumatic suction cups or plates forming horizontal bottom plates 3b1 supported by said fork and suitable for bearing against and fastening to the underside of the hull of the second vessel.

[0071] In all three embodiments, the cantilevered-out tubular elements 33b are themselves supported by junction tubular elements 33a that serve to connect them with the tower, and said fork 33 may bear against and be fastened to the underside of the hull 11b-11c of the second vessel 11.

[0072] The coupling device 1 shown in FIGS. 1A-1B, 2A-2B, and 3B has three actuators 21, 22, and 23, two actuators 21-22 in FIG. 3A, and four actuators 21-24 in FIG. 3C. The actuators 21-24 are single-chamber or telescopic actuators and they are double-acting. The various actuators are spaced apart successively from one another in the longitudinal direction of the first vessel 10 and of the tower 3. At one end, each actuator is fastened to a high portion above the water of the tower of the floating structure 3, and at its other end it is fastened to or for fastening to a high portion above the water of the hull 10a of the first vessel 10 so as to be capable, in the deployed position, of extending over the surface of the water 12.

[0073] More precisely, for each actuator, rear end plates of the actuator cylinder 2a are fastened via a hinge device 2c1 to the hull 10a of the first vessel 10, and the end of the actuator rod 2b is fastened via a hinge device 2c2 at the top portion of a floating and docking structure 3 that enables the device to float and that enables the vertical position of the assembly to be adjusted.

[0074] The fastener and hinge devices 2c1 and 2c2 shown in FIG. 4 provide two degrees of freedom to move in pivoting about two perpendicular pivot axes comprising a system allowing a first pivoting of said actuator about a horizontal first pivot axis perpendicular to the longitudinal axis of the actuator, namely X1X1 for 2c1 and X2X2 for 2c2, and second pivoting of said actuator about a second pivot axis namely Y1Y1 for 2c1 and Y2Y2 for 2c2, that is perpendicular to the longitudinal axis of the actuator situated in a vertical plane containing the longitudinal axis of the actuator.

[0075] Each of the fastener and hinge devices 2c1 and 2c2 comprises an intermediate independent connection part 2e1, 2e2, each comprising: [0076] a first portion comprising two branches forming a first clevis 2e1, 2e2 co-operating with a first fastener plate 2d1 secured to the end of the actuator cylinder 2a for 2c1 and to a second fastener plate 2d2 secured to the end of the actuator rod 2b for 2c2; and [0077] a second portion forming a third fastener plate 2e1, 2e2 co-operating with two branches forming a second clevis 2f1 secured to the vessel 10 for 2c1 and respectively a third clevis 2f2 secured to a tube 31 of the structure 3 for 2c2.

[0078] For each fastener and hinge device 2c1, 2c2, the first pivot axis X1X1 and X2X2 passes through orifices in the two branches of the first clevis 2e1, 2e2 and an orifice in said first or second fastener plate 2d1 or 2d2 respectively arranged between the two branches of the first clevis so that said first or second fastener plate 2d1, 2d2 is suitable for pivoting about the horizontal first axis X1X1 or X2X2 relative to said intermediate independent connection parts 2e1, 2e2; and [0079] said second axis Y1Y1, Y2Y2 passes through orifices in the two branches of the second clevis 2f1 or respectively the third clevis 2f2 and passes through an orifice in said third fastener plate 2e1, 2e2 arranged between the two branches of the second and third devises in such a manner that said third fastener plate is suitable for pivoting about the second axis Y1Y1, Y2Y2 relative to said intermediate independent connection part 2e1, 2e2.

[0080] Preferably, the actuator rod 2a is also suitable for turning about its own axis in the actuator cylinder 2b, so that the actuator thus forms a swivel connected to the two devices 2c1 and 2c2 and allowing a third pivoting movement about the longitudinal direction of the actuator.

[0081] Alternatively, use is made of a pivot fastener and hinge device of the ball joint type. The ball joints used for said first and second pivot fastener and hinge devices are typically mechanical elements having a ball embedded in a spherical housing, thus enabling the actuators to work only axially in sliding.

[0082] The coupling device 1 is typically secured to the first vessel 10 of the FLNG type using the actuators while in the retracted position, each having one end 2c1 fastened to the flank or side 10a of the first vessel.

[0083] When the coupling device 1 is not in use, in particular in a storm, it is put into a safe or stowed position: the actuators 2, 21-24 are retracted and positioned so as to be folded upwards above their ends 2c1 against the hull of the first vessel, with the floating and docking structure 3 put in a high position by at least partially de-ballasting said float(s) 3a so as to be capable of following the actuators and allowing them to pivot until the maximally retracted actuators are in a substantially vertical position with said floating and docking structure 3 fastened to said actuators via said second fastener and hinge devices 2c2, the assembly of the actuators and the floating structure 3 being pressed, while at least in part out of the water, against the hull of the first vessel, as shown in FIGS. 1A-1B and 2B. The floating and docking structure 3 is attached to the second vessel, typically an LNGC (LNG carrier) by performing the following successive steps: [0084] with the set of actuators 2, 21-24 and the floating structure 3 pressed at least in part out of the water against the hull of the first vessel, as shown in FIGS. 1A-1B and 2B, said float(s) is/are ballasted in order to immerse said floating and docking structure 3 to the appropriate depth, and simultaneously said actuators are pivoted and deployed by hydraulic actuation to a sloping position above the surface of the water 12, preferably sloping at an angle of less than 15 relative of the horizontal; [0085] thereafter, the assembly comprising the first vessel and said coupling device that is fastened thereto is moved towards the second vessel, or preferably given that the first vessel is generally anchored, it is the second vessel that is moved by tug into the proximity of the first vessel and of said coupling device that is fastened thereto; then [0086] once facing the second vessel, the floats 3a1-3a4, 3a1-3a4 are ballasted to lower the plates 3b facing the hull, in particular the bottom plates 3b, 3b1 on the top face of the fork 33 under the hull 11b, 11c of the second vessel 11; then [0087] the floats 3a1-3a4, 3a1-3a4 are de-ballasted again so that the bottom plates 3b, 3b1 rise and come to press against and/or face the bottom of the hull 11a of the second vessel 11; and [0088] said plates are actuated to become fastened against the hull of the second vessel, in particular by using the magnetic fastener suction cups they include (3b, 3b1-3b2).

[0089] In FIGS. 3A and 3B, the coupling device 1 has three actuators 21-23, comprising a central actuator 22 and two actuators 21 and 23 suitable for being arranged symmetrically relative to the central actuator. Thus, when the actuators are deployed and fastened to the floating structure 3, the central actuator 22 lies in a vertical plane perpendicular to the vertical plane that is tangential to the side 10 of the first vessel 10, while the actuators 21 and 23 are arranged symmetrically in vertical planes that slope at an angle of less than 30 relative to a vertical plane perpendicular to the vertical plane that is tangential to the side of the first vessel 10.

[0090] In FIG. 3C, the four actuators 21-24 are arranged as two pairs of actuators 21-22 and 23-24 each forming a V-shape when they are deployed and fastened to the floating structure 3. The distance between the tip 2c2 of the actuator 24 and the corresponding tip of the actuator 21 on the coupling device is about 80 m. The distance between the tip 2c1 of the actuator 24 and the corresponding tip of the actuator 21 on the side of the first vessel is L0=140 m. The spacings L4=60 m of the two actuators in each pair 24-23 and 22-21 are greater beside their fastenings 2c1 to the hull of the first vessel than the spacings of their fastenings 2c2 on the floating structure 3, which are close to one another. The various actuators 21-24 are arranged in a vertical plane sloping at an angle of less than 30 degrees relative to a vertical plane perpendicular to the vertical plane that is tangential to the side of the first vessel.

[0091] In all of the embodiments, the actuators are also arranged to slope relative to a horizontal plane at an angle of less than 15 degrees.

[0092] In its top portion, said floating and docking structure 3 may advantageously support troughs for supporting flexible pipes extending out of the water between said first and second vessels arranged side by side.

[0093] It is possible to use four actuators 21-24 each having a rating of 250 metric tonnes (T), the actuator rods being suitable for moving over a stroke of 5 m to 10 m, in particular for docking together two vessels that are 150 m to 300 m long.

[0094] More particularly, an actuator stroke of 5 m with actuator lengths in the range 10 m to 15 m enables the vessels to be spaced apart by 30 m to 34 m, or indeed a stroke of 10 m leads to actuator lengths in the range 22 m to 24 m for spacing between the vessels of 40 m to 44 m.

[0095] Once the coupling device 1 is attached to the second vessel 11, it is capable of keeping the two vessels at a constant mean distance apart in spite of weather environments, either passively or else by appropriate hydraulic control.

[0096] With said actuators initially deployed in a medium extension position when coupling said floating and docking structure that is fastened to said actuators with said second vessel, and with a said float that is ballasted, as shown in FIG. 2A, the extension of said actuators is operated and/or automatically controlled so that said actuators and the two vessels remain in their initial position or return towards their initial position with a distance between the two vessels that is controlled in the event of them moving apart.

[0097] Because of the long stroke of the actuators, the two vessels interact dynamically with each other relatively little. The forces taken up by the device are forces that are averaged and not impact forces. Because of this feature, it is possible to keep the vessels together even when the swell becomes strong (swells of about 4 m can typically be withstood).

[0098] In order to optimize the position of the ships and the forces in the device, the actuators may be controlled in three ways: [0099] linear passive control: the actuators behave like springs of linear response regardless of the position of the rods within the cylinders; [0100] non-linear passive control: the actuators behave like springs with stiffness that depends on the position of each rod within the cylinder of the actuator; and [0101] non-linear active control: the stiffness of the actuators is adapted instantaneously under the control of software analyzing the relative position of the two vessels. With said actuators 21, 22, 23 being initially deployed in a medium extension position for coupling purposes and with said floating and docking structure 3 fastened to said actuators and to said second vessel, and with said float ballasted, said floating and docking structure 3 is separated from said second ship, and then said actuators are retraced and said float 3a is de-ballasted so as to press the assembly while at least partially out of the water against the hull of the first vessel as described above.